1. Field of the Disclosure
The present disclosure is related to methods and apparatus for estimating a rock strength profile of a wellbore formation in-situ.
2. Description of the Related Art
In petroleum exploration, drilling a wellbore or borehole in an earth formation employs a drill string with a drill bit at an end of the drill string. The speed and effectiveness of drilling is determined in part on the type of rock that is being drilled and its hardness or strength. Various types of rock that can be drilled can range from hard rocks such as granites and dolomites to soft rocks such as sandstones and shales. Various devices for estimating rock hardness are known in the art. However, these require obtaining a core sample and retrieving the sample to a surface location for testing, which can be time-consuming and expensive. Therefore, the present disclosure provides a method and apparatus for estimating in-situ a rock strength profile of a formation.